The objectives of this study are: To assess the safety of and determine the maximum tolerated dose of intravenous rhu (CHO) IL-1R in cancer patients. To measure the pharmacokinetic profile of intravenous rhu (CHO) IL-1R in cancer patients. To determine either the effective biologic dose (EBD) as defined by inhibition of IL-2-induced CRP release or the maximum tolerated dose (MTD) of rhu (CHO) IL-1R (administered up to a maximum of 55 mg/m2 in patients undergoing high dose IL-2 therapy).